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1.
Outlook Agric ; 50(2): 116-124, 2021 Jun.
Article in English | MEDLINE | ID: mdl-34366487

ABSTRACT

How to stimulate technological change to enhance agricultural productivity and reduce poverty remains an area of vigorous debate. In the face of heterogeneity among farm households and rural areas, one proposition is to offer potential users a 'basket of options' - a range of agricultural technologies from which potential users may select the ones that are best suited to their specific circumstances. While the idea of a basket of options is now generally accepted, it has attracted little critical attention. In this paper, we reflect on outstanding questions: the appropriate dimensions of a basket, its contents and how they are identified, and how a basket might be presented. We conceive a basket of options in terms of its depth (number of options related to a problem or opportunity) and breadth (the number of different problems or opportunities addressed). The dimensions of a basket should reflect the framing of the problem or opportunity at hand and the objective in offering the basket. We recognise that increasing the number of options leads to a trade-off by decreasing the fraction of those options that are relevant to an individual user. Farmers might try out, adapt or use one or more of the options in a basket, possibly leading to a process of technological change. We emphasise that the selection (or not) of specific options from the basket, and potential adaptation of the options, provide important opportunities for learning. Baskets of options can therefore be understood as important boundary concepts that invite critical engagement, comparison and discussion. Significant knowledge gaps remain, however, about the best ways to present the basket and to guide potential users to select the options that are most relevant to them.

2.
Agric Syst ; 175: 1-12, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31582872

ABSTRACT

We evaluated the usefulness of a co-design process to generate a relevant basket of options for climbing bean cultivation in the context of a large-scale project. The aim was to identify a range of options sufficiently diverse to be of interest for farmers of widely-different resource endowment. The co-design process consisted of three cycles of demonstration, evaluation and re-design in the eastern and southwestern highlands of Uganda in 2014-2015. Evaluations aimed to distinguish preferences of farmers between the two areas, and among farmers of different gender and socio-economic backgrounds. Farmers, researchers, extension officers and NGO staff re-designed treatments for demonstrations in the next season. Climbing bean yields and evaluation scores varied between seasons and sites. Evaluation scores were not always in line with yields, revealing that farmers used multiple evaluation criteria next to yield, such as marketability of varieties, availability of inputs and ease of staking methods. The co-design process enriched the basket of options, improved the relevance of options demonstrated and enhanced the understanding of preferences of a diversity of users. Developing options for resource-poor farmers was difficult, however, because they face multiple constraints. The basket of options developed in this study can be applied across the East-African highlands, with an 'option-by-context' matrix as a starting point for out-scaling. The study also showed, however, that consistent recommendations about the suitability of technologies for different types of farmers were hard to identify. This highlights the importance of a basket of options with flexible combinations of practices rather than developing narrowly specified technology packages for static farm types.

3.
Agric Ecosyst Environ ; 261: 186-200, 2018 Jul 01.
Article in English | MEDLINE | ID: mdl-29970947

ABSTRACT

Climbing beans offer potential for sustainable intensification of agriculture, but their cultivation constitutes a relatively complex technology consisting of multiple components or practices. We studied uptake of improved climbing bean production practices (improved variety, input use and management practices) through co-designed demonstrations and farmer-managed adaptation trials with 374 smallholder farmers in eastern and southwestern Uganda. A sub-set of these farmers was monitored one to three seasons after introduction. About 70% of the farmers re-planted climbing beans one season after the adaptation trial, with significant differences between eastern (50%) and southwestern Uganda (80-90%). Only 1% of the farmers used all of the improved practices and 99% adapted the technology. On average, farmers used half of the practices in different combinations, and all farmers used at least one of the practices. Yield variability of the trials was large and on average, trial plots did not yield more than farmers' own climbing bean plots. Yet, achieved yields did not influence whether farmers continued to cultivate climbing bean in the subsequent season. Uptake of climbing beans varied with household characteristics: poorer farmers cultivated climbing beans more often but used fewer of the best-bet practices; male farmers generally used more practices than female farmers. Planting by poorer farmers resulted in adaptations such as growing climbing beans without fertilizer and with fewer and shorter stakes. Other relationships were often inconsistent and farmers changed practices from season to season. The diversity of farmer responses complicates the development of recommendation domains and warrants the development of a basket of options from which farmers can choose. Our study shows how adoption of technologies consisting of multiple components is a complicated process that is hard to capture through the measurement of an adoption rate at a single point in time.

4.
Neth Heart J ; 24(3): 173-80, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26860709

ABSTRACT

BACKGROUND: The OPTIMA trial was a randomised multicentre trial exploring the influence of the timing of percutaneous coronary intervention (PCI) on patient outcomes in an intermediate to high risk non-ST-elevation acute coronary syndrome (NSTE-ACS) population. In order to decide the best treatment strategy for patients presenting with NSTE-ACS, long-term outcomes are essential. METHODS: Five-year follow-up data from 133 of the 142 patients could be retrieved (94 %). The primary endpoint was a composite of death and spontaneous myocardial infarction (MI). Spontaneous MI was defined as MI occurring more than 30 days after randomisation. Secondary endpoints were the individual outcomes of death, spontaneous MI or re-PCI. RESULTS: No significant difference with respect to the primary endpoint was observed (17.8 vs. 10.1 %; HR 1.55, 95 % CI: 0.73-4.22, p = 0.21). There was no significant difference in mortality rate. However, spontaneous MI was significantly more common in the group receiving immediate PCI (11.0 vs. 1.4 %; HR 4.46, 95 % CI: 1.21-16.50, p = 0.02). We did not find a significant difference between the groups with respect to re-PCI rate. CONCLUSION: There was no difference in the composite of death and spontaneous MI. The trial suggests an increased long-term risk of spontaneous MI for patients treated with immediate PCI.

5.
Heart ; 95(10): 807-12, 2009 May.
Article in English | MEDLINE | ID: mdl-19098058

ABSTRACT

BACKGROUND: The field of acute coronary syndromes is characterised by an increasing tendency towards early invasive catheter-based diagnostics and therapeutics-a practice based on observational and retrospective data. OBJECTIVE: To compare immediate versus deferred angioplasty in patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) METHODS: A randomised, prospective multicentre trial was performed in patients admitted with NSTE-ACS, eligible for percutaneous coronary intervention (PCI). Interim analysis was performed after enrolment of 251 patients; PCI was appropriate in 142 patients. These patients were randomised to immediate PCI (n = 73) or deferred PCI (24-48 h) (n = 69). Patients received protocol-driven glycoprotein IIb/IIIa blockers, aspirin and clopidogrel. The primary end point was a composite of death, non-fatal myocardial infarction (MI) or unplanned revascularisation, at 30 days. After hospital discharge outpatient follow-up was performed at 30 days and 6 months. RESULTS: The incidence at 30 days of the primary end point was 60% in the group receiving immediate PCI and 39% in the group receiving deferred PCI (relative risk (RR) = 1.5, 95% CI 1.09 to 2.15; p = 0.004). No deaths occurred in either group. MI was significantly more common in the group receiving immediate PCI (60% vs 38%, RR = 1.6, 95% CI 1.12 to 2.28, p = 0.005). Unplanned revascularisation was similar in both groups. The observed difference was preserved over 6-months' follow-up. CONCLUSIONS: Immediate PCI was associated with an increased rate of MI in comparison with a 24-48 h deferred strategy, despite aggressive antithrombotic treatment. The results suggest that PCI for high-risk patients with non-refractory NSTE-ACS should be delayed for at least 24 h after hospital admission. TRIAL REGISTRATION NUMBER: ISRCTN80874637.


Subject(s)
Acute Coronary Syndrome/therapy , Angioplasty, Balloon, Coronary , Myocardial Infarction/epidemiology , Acute Coronary Syndrome/mortality , Angioplasty, Balloon, Coronary/adverse effects , Aspirin/therapeutic use , Clopidogrel , Female , Humans , Incidence , Male , Middle Aged , Myocardial Infarction/mortality , Platelet Aggregation Inhibitors/therapeutic use , Prospective Studies , Ticlopidine/analogs & derivatives , Ticlopidine/therapeutic use , Time Factors , Treatment Outcome
6.
Eur Heart J ; 23(19): 1529-37, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12242073

ABSTRACT

In order to study the safety of 'rescue' strategies in the treatment of patients with failed thrombolysis, all 548 patients admitted with evolving myocardial infarction to the Thoraxcenter, Rotterdam, from January 1997 until April 1999 were reviewed. Of these patients, 49% had received thrombolysis. Of patients treated with thrombolysis and not referred from other hospitals (n = 154) 36% received rescue therapy for failed thrombolysis. Three rescue therapies were used after failed thrombolysis: percutaneous coronary intervention (74%), retreatment with thrombolysis (39%) and platelet glycoprotein (GP) IIb/IIIa receptor blockers (53%), often in combination. Platelet GP IIb/IIIa receptor blockers were administered in 64% of patients treated with rescue percutaneous coronary intervention. Major bleeding occurred in 14% of all thrombolysis treated patients, and in 30% of patients who received multiple rescue therapies. Bleeding was related to heparin usage and platelet GP IIb/IIIa receptor blockers, as was the insertion of catheters for percutaneous coronary intervention or intra-aortic balloon pumps. Major bleeding resulted in one death due to a ruptured ventricle, one haemorrhagic stroke, and three cases of tamponade for which surgery was needed. Four of these patients had received combination rescue therapy. Rescue therapy is a widely used strategy for failed thrombolysis, but is associated with a high bleeding rate. Alternative reperfusion strategies to avoid failed thrombolysis should be considered in high risk patients.


Subject(s)
Myocardial Infarction/therapy , Platelet Glycoprotein GPIIb-IIIa Complex/antagonists & inhibitors , Platelet Glycoprotein GPIIb-IIIa Complex/therapeutic use , Thrombolytic Therapy , Angioplasty, Balloon, Coronary , Combined Modality Therapy , Female , Fibrinolytic Agents/therapeutic use , Heart Ventricles/pathology , Heart Ventricles/surgery , Hemorrhage/etiology , Hemorrhage/mortality , Hemorrhage/therapy , Heparin/therapeutic use , Humans , Intra-Aortic Balloon Pumping , Male , Middle Aged , Myocardial Infarction/complications , Myocardial Infarction/mortality , Netherlands/epidemiology , Reoperation , Reperfusion , Retrospective Studies , Survival Analysis , Tissue Plasminogen Activator/therapeutic use , Treatment Failure
7.
Eur Heart J ; 23(3): 239-46, 2002 Feb.
Article in English | MEDLINE | ID: mdl-11792139

ABSTRACT

BACKGROUND: Many patients with acute coronary syndromes are offered percutaneous coronary intervention. However, the appropriate indications for, and optimal timing of, such procedures are uncertain. We analysed timing of intervention and associated events (death and myocardial infarction) in the PURSUIT trial in which 9461 patients received a platelet glycoprotein IIb/IIIa inhibitor, eptifibatide, or placebo for 72 h. Other treatment was left to the investigators. 2430 patients underwent percutaneous coronary intervention within 30 days. Four groups were distinguished, who underwent percutaneous coronary intervention on day 1; on days 2 or 3; at 4 to 7 days; or between 8 until 30 days, for eptifibatide- and placebo-treated patients. RESULTS: The four groups treated with placebo demonstrated total 30-day events of 15.9% for day 1 percutaneous coronary intervention, 17.7%, 15.0% and 18.2%, respectively, for successive intervals of later intervention. Later intervention was associated with more pre-procedural events (2.2% to 13.7%, P=0.001) which was balanced by a decrease in procedure-related events (12.1 to 3.1%, P=0.001), while the overall 30-day event rates were similar. Eptifibatide-treated patients with percutaneous coronary intervention on day 1 had the lowest rate of 30-day events (9.2%, P<0.05 vs other groups). In this group, pre-procedural risk was only 0.3%, while percutaneous coronary intervention on eptifibatide treatment was associated with low procedural risk (7.2%). The total 30-day event rate for later percutaneous coronary intervention in patients receiving eptifibatide was 14.0 on days 2 and 3, 15.0% for days 4 to 7 and 17.4% for days 7 to 30, respectively. CONCLUSION: Patients treated with a platelet glycoprotein IIb/IIIa receptor blocker, and early percutaneous coronary intervention (within 24 h) had the lowest event rate in this post hoc analysis. Thus 'watchful waiting' may not be the optimal strategy. Rather an early invasive strategy with percutaneous coronary intervention under protection of a platelet glycoprotein IIb/IIIa receptor blocker should be considered in selected patients. Randomized trials are warranted to verify this issue.


Subject(s)
Angioplasty, Balloon, Coronary , Coronary Disease/therapy , Electrocardiography , Platelet Glycoprotein GPIIb-IIIa Complex/antagonists & inhibitors , Platelet Glycoprotein GPIIb-IIIa Complex/therapeutic use , Platelet Glycoprotein GPIb-IX Complex/antagonists & inhibitors , Platelet Glycoprotein GPIb-IX Complex/therapeutic use , Platelet Membrane Glycoproteins , Acute Disease , Combined Modality Therapy , Coronary Disease/complications , Coronary Disease/mortality , Endpoint Determination , Eptifibatide , Female , Follow-Up Studies , Humans , Male , Middle Aged , Peptides/antagonists & inhibitors , Peptides/therapeutic use , Placebos , Postoperative Complications/etiology , Postoperative Complications/mortality , Survival Analysis , Syndrome , Time Factors , Treatment Outcome
8.
Eur Heart J ; 21(18): 1530-6, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10973767

ABSTRACT

AIMS: Thrombolytic therapy restores coronary patency in patients with acute myocardial infarction, although normal perfusion (TIMI 3 flow) is not achieved in all patients. In an attempt to improve TIMI 3 flow, a combination of full-dose streptokinase, aspirin and escalating dosages of a platelet glycoprotein IIb/IIIa receptor blocker, eptifibatide, vs placebo were tested. METHODS AND RESULTS: A bolus of 180 microg. kg(-1)of eptifibatide was administered in each group, followed by a 72 h continuous infusion of 0.75 (44 patients), 1.33 (n=45) and 2.00 microg. kg(-1). min(-1)(n = 30); 62 patients received placebo. Normal perfusion (TIMI 3 flow) at 90 min was observed in 31% of placebo patients compared to 46, 42 and 45% in the ascending eptifibatide groups (44% for combined eptifibatide groups, P = 0.07). Patency (TIMI 2 and 3 flow combined) increased from 61% (placebo) to 78% for the combined eptifibatide groups (P = 0.02). Reocclusion was infrequent. No differences were observed in TIMI flow grades among eptifibatide groups. Major and minor bleeding was increased and occurred mainly at the arterial puncture site. CONCLUSION: A combination of full dose streptokinase with different eptifibatide regimens enhanced coronary perfusion, but bleeding risk was excessive. Additional trials are needed with different dosage regimens to determine the optimal combination of fibrinolytic agents and platelet glycoprotein IIb/IIIa receptor blockers.


Subject(s)
Myocardial Infarction/drug therapy , Peptides/therapeutic use , Platelet Aggregation Inhibitors/therapeutic use , Thrombolytic Therapy , Adult , Aged , Aspirin/therapeutic use , Double-Blind Method , Drug Therapy, Combination , Eptifibatide , Female , Fibrinolytic Agents/therapeutic use , Humans , Male , Middle Aged , Peptides/administration & dosage , Platelet Aggregation Inhibitors/administration & dosage , Streptokinase/therapeutic use , Treatment Outcome
12.
Eur J Pharmacol ; 173(2-3): 227-31, 1989 Dec 07.
Article in English | MEDLINE | ID: mdl-2576230

ABSTRACT

The administration of the dopamine D-1 receptor antagonist, SCH 23390, but not of the dopamine D-2 receptor antagonist, sulpiride, suppressed the excessive grooming induced by a new environment or by various neuropeptides. In addition, administration of the dopamine D-1 agonist, SK & F 38393, induced excessive grooming but that of the dopamine D-2 agonist, quinpirole, did not. It is suggested that dopamine D-1 rather than D-2 receptor stimulation is an important mechanism underlying novelty-induced as well as neuropeptide-induced excessive grooming.


Subject(s)
Dopamine Agents/pharmacology , Dopamine Antagonists , Grooming/drug effects , Neuropeptides/pharmacology , Receptors, Dopamine/drug effects , 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology , Animals , Benzazepines/pharmacology , Ergolines/pharmacology , Male , Quinpirole , Rats , Rats, Inbred Strains , Sulpiride/pharmacology
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